1. Field of Invention
The present invention relates to the video compression and decompression techniques, and particularly relates to the video compression for simplifying the compression procedure and reducing the requirements of image buffer size, I/O bandwidth and the power consumption.
2. Description of Related Art
In the past decades, the semiconductor technology migration trend has driven the digital image and video compression and display feasible and created wide applications including digital still camera, digital video recorder, web camera, 3G mobile phone, VCD, DVD, Set-top-box, Digital TV, . . . etc.
Most commonly used video compression technology like the MPEG and JPEG take the procedure of image and video compression in the YUV (Y/Cr/Cb) pixel format which is from converting the digitized raw color data with one color component per pixel to three color components (Red, Green and Blue or so named RGB) per pixel and further converting to YUV as shown in the prior art procedure of image/video compression and display in FIG. 1. Most video compression algorithms require that the image sensor transfer the image pixels to a temporary image buffer for compression, under this kind mechanism, the pixel data amount shoots to three components from only one captured in the image sensor which requires quite a lot storage device density and needs a temporary buffer to store it. Data transferring from the image sensor to the temporary image buffer and back to the video compression engine causes delay time and requires high I/O bandwidth in data transferring and dissipates quite high power consumption.
This invention takes new alternatives and more efficiently overcomes the setbacks of prior art video compression with much less cost of semiconductor die area and chip/system packaging. With the invented method, an apparatus of integrating most image and video compression function with the image sensor chip or a smaller module becomes feasible.